help with my HP prime
|
12-16-2016, 02:57 PM
(This post was last modified: 12-16-2016 03:30 PM by pedroHPsp.)
Post: #1
|
|||
|
|||
help with my HP prime
Yesterday I was doing an structures exam with my brand new HP prime.
At the end of one of the problems i had to solve a linear system of equations (KX=F) where K is the stiffness matrix. the problem came when i tried to solve it using the linear solver app, the system was something like: 5e11X+6e11Y=50000 6e11X+12e11Y=6000 the calculator just gave me X=0 Y=0. I tried to solve it manually by calculating the inverse matrix of [[5e11,6e11],[6e11,12e11]] and the result was a matrix of zeros [[0,0],[0,0]]. after trying a couple of times I just took my old 50g from my backpack and solved the system without problems. later in my house i tried again and always the result was a matrix of zeros when trying to invert a matrix with big coefficients, and also the same in my computerĀ“s HP prime virtual calculator. reading the primeĀ“s manual i found that the calculator does not manage numbers smaller than 1e-49 but its far away from the expected results of the equation system (values around 1e-4). also i found that there is no problem using the CAS mode or using approx([5e11,6e11],[6e11,12e11]]^-1) but i don't know why. thanks god i had my 50g but i don't understand why i can't make the inverse matrix in the prime if i can do it even with a casio basic calculator. pedro civil engineering student madrid (Spain) |
|||
« Next Oldest | Next Newest »
|
Messages In This Thread |
help with my HP prime - pedroHPsp - 12-16-2016 02:57 PM
RE: help with my HP prime - Han - 12-16-2016, 03:50 PM
RE: help with my HP prime - pedroHPsp - 12-16-2016, 03:59 PM
RE: help with my HP prime - Han - 12-16-2016, 06:50 PM
RE: help with my HP prime - Arno K - 12-16-2016, 06:53 PM
RE: help with my HP prime - toshk - 12-16-2016, 07:27 PM
RE: help with my HP prime - pedroHPsp - 12-16-2016, 07:27 PM
|
User(s) browsing this thread: 1 Guest(s)